Modes of Operation
The LL-RLP-20 or LL-RXR-27 module is designed to be controlled by an external host microcontroller. Link Labs has developed a host interface to operate the module in Symphony Link mode or NoMAC mode. These modes are described below.
Symphony Link Mode
Symphony Link is Link Labs' proprietary over-the-air protocol. It implements a star network based on a slotted Aloha scheme. A simple Symphony Link network is pictured in the figure, above.
In Symphony Link mode, the LL-RLP-20 or LL-RXR-27 module participates as an endpoint with compatible Symphony Link networks. The module automatically connects to an in-range Symphony Link gateway. The gateway relays uplink messages from the module to Conductor, Link Labs' cloud-based data services platform. Likewise, the gateway relays downlink messages sent from Conductor to individually addressed modules.
In Symphony Link mode, the module is controlled using a small set of high-level functions. The details of network operation -- timing, frequency selection, data rate, transmit power, encryption, etc -- are automatically controlled by handshaking between the module and the gateway to optimize network capacity, range and power consumption.
NoMAC mode disables the media access control (MAC) firmware and allows the host system to issue low-level commands. NoMAC mode gives the host system direct control of the module's radio parameters, without any automatic network control. NoMAC is useful for network research and development while designing or experimenting with new MAC protocols.